Right Unilateral Electroconvulsive Therapy Treatment for CRPS
The use of electric fish/eels in pain treatment has been documented to Roman times,1 and electroconvulsive therapy (ECT) has been known to relieve chronic pain since the 1940’s—including the complete remission of chronic cases of what has become known as CRPS-1 since at least 1957.2 Yet even with many modifications in the therapy that have ensued, physicians have remained reluctant to utilize ECT, primarily because of the concern of injury and the negative image associated with ECT.1 The side-effect of greatest concern is retrograde amnesia, which has been significantly associated with Bilateral ECT (BL), the dominant form of the treatment. Nevertheless, a series of case reports going back to 19753 give strong support that, contrary to accepted wisdom, an alternative form of treatment—often referred to as Right-Unilateral (RUL) ECT, but more properly characterized as “non-dominant unilateral”—has equivalent effectiveness in the treatment of certain forms of chronic pain—including CRPS—without persistent cognitive side effects. Such treatment should therefore be considered for refractory cases of CRPS-1.
Among various forms of chronic pain, CRPS has stood out as a condition that tends to respond well to a series of typically between six and twelve ECT treatments, resulting in significant and long lasting improvement in approximately two out of three cases.1,2,4-6 Of six case studies, the most recent report is perhaps the most dramatic: over a period of time following one automobile accident in which she suffered a flexion-extension injury to her neck, and a second accident three years later in which she fractured her left wrist, a woman who had been working as a judge, developed severe CRPS in all of her extremities, back and face—along with internal complications—to the point that she became too ill to work. Notwithstanding extensive treatments, including a four-day course of inpatient IV lidocaine, the patient had no relief from pain four years from the time of her initial accident. Finally, two years later and after developing severe, medically refractory depression, the patient received a series of 12 BL ECT treatments under standard anesthesia. Within a month she reported an almost complete remission of her CRPS symptoms. Four years later, in 2007, the patient was seen again, at which time she had no criterion factors for CRPS or depression, and had returned to a normal life working full-time as an attorney.6
Notwithstanding the fact that most, if not all, of the patients referred to in the case studies above had co-morbid depression, it has been established in an inpatient study at the Chronic Pain Treatment Service of the Johns Hopkins Department of Psychiatry and Behavioral Medicine that ECT has a demonstrable effect on chronic pain independent of the patient’s level of depression or degree of recovery. The study used a matching system where each ECT patient was matched to another patient—based as much as possible on race, pain syndrome diagnosis, and number of previous psychiatric hospitalizations—who would be receiving medication only. Of the 36 patients beginning the ECT treatment, 28 completed charts remained at the end of the study. Of those, 25 could be matched—with 3 members of the control group being used twice for matching purposes. The major findings of the study are as follows:
“The data presented here indicate that ECT has analgesic properties independent of its effect on depression in patients with both chronic pain and major depression. Improvements in depression scores were statistically similar between groups, while improvements in pain were greater in the ECT group. Of great interest is that, despite starting at a higher pain level (8.1 vs 6.9), the ECT group had a lower level of pain at the end of treatment (3.4) than the control group (5.5), who were treated with medications alone. The difference in baseline pain scores between groups may be a confounder, but the more profound drop in pain score to below a 4.0 in the ECT group speaks against this. The ECT group improved to a pain level lower than 4.0, which is a level consistent with significant gains in functionality, while the control group remained above 4.0. Their lower post-treatment pain scores suggest a specific analgesic effect of ECT. The significant partial correlation coefficient controls for the effect of the improvements in depression between groups and affirms the analgesic properties of ECT. The longer length of stay in the ECT group (40 vs 20 days) may have contributed to their improvements in pain, since they received more multidisciplinary treatment. But, patients in the ECT group had an average of 10 treatments, and they were unable to fully participate in multidisciplinary treatment on those days. This mitigates the confounding effects of longer length of stay on analgesic response. The number of patients in each specific pain diagnosis group was too small to determine if a particular pain syndrome responded preferentially to ECT. But, these data indicate that ECT has analgesic effects across a wide variety of pain syndromes.
“While the ECT group had a more robust improvement in major depression, this improvement was not significantly different between the groups. This finding is consistent with previous studies showing a depression treatment response rate of up to 90% with ECT, while, on average, antidepressant treatment has an 80% response rate.”7
As alternative forms of ECT were developed to minimize cognitive side effects (persistent retrograde amnesia), at least one early report had shown that RUL was effective for chronic pain—providing persistent relief for four of six patients.3 Unfortunately, those findings, along with a study showing no improvement in post-stroke thalamic pain,8 were subsequently characterized as supporting the proposition that “while the use of unilateral electrode placement over the non-dominant frontal lobe reduced confusion, it may have resulted in lower response rates of intractable pain to ECT and subsequent abandonment of the procedure for pain syndromes.”9 This conclusion has since been repeatedly cited in the literature for the proposition that only Bilateral ECT was effective for the treatment of chronic pain.5,6 It was, however, specifically challenged in one 2003 report of a CRPS-1 patient having had eight treatments of RUL, sustaining complete remission of both depression and CRPS.5
We are left with the fact that, to date, there have been no double-blind controlled studies of the respective efficacies of BL and RUL for chronic pain—an issue addressed in a somewhat more general context by Rasmussen and Rummans in their comprehensive 2002 review: